1. Field of the Invention
This invention pertains generally to loadcenters and, more particularly, to loadcenters accommodating critical loads and non-critical loads being supplied with power from separate generators in response to power from a utility service becoming unacceptable. This invention also relates to methods of distributing power from separate generators to critical loads and non-critical loads.
2. Background Information
Loadcenters incorporating a multitude of circuit breakers to provide a safe and controllable distribution of electrical power have become a common feature in both residential and commercial structures. Increasingly, such loadcenters are utilized in installations that incorporate an electric generator as a second power source in the event that a utility service serving as a first power source fails or becomes unreliable.
With technological progress resulting in ever more uses for electricity, the amount of electrical power required for both residential and commercial structures has steadily increased, and this had lead to increased demand for relatively larger electric generators. Unfortunately, relatively larger electric generators present various disadvantages over relatively smaller electric generators. While smaller electric generators are typically air cooled, larger electric generators typically require a liquid cooling system with a circulation pump and radiator, thereby adding to both the costs and complexities of operating and maintaining a larger generator in comparison to a smaller generator. Larger generators also require relatively larger quantities of maintenance fluids, including lubrication oil and coolant liquid.
Given the disadvantages of larger generators in comparison to smaller generators, there has been interest in combining multiple smaller generators to do the work of a larger generator. However, combining the output of multiple generators is hampered by the AC outputs of independent generators often being out of phase. Known techniques for combining such unsynchronized supplies of power into a single supply of power with acceptable alternating current (AC) characteristics are both cumbersome and expensive.
Technological progress has also spurred a growing use of uninterruptible power supply (UPS) units in both residential and smaller scale commercial structures to provide reliable electric power for doctor's offices away from hospitals, home-based businesses and home-based chronic patient care support. Unfortunately, typical commercially available uninterruptible power supplies are standalone device that are typically placed directly in rooms where they are needed, and are not designed to coordinate their operation of providing uninterrupted power to ultra-critical loads with the operation of electric generators to most efficiently ensure the provision of electric power to different loads of differing priority.